共查询到18条相似文献,搜索用时 140 毫秒
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针对飞参数据的特点,从野值剔除和属性选择两个方面对飞参数据预处理进行了研究,提出了基于残差检验的野值剔除方法和基于神经网络的两阶段属性选择方法。在野值剔除方法中,首先计算原始序列和拟合序列的残差,再用门限值对残差进行检验;在属性选择方法中,先用神经网络对属性的相对重要度进行排序,再用神经网络进行属性选择。最后用实验验证了两方法的有效性。 相似文献
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针对飞参数据的特点.从野值剔除和属性选择两个方面对飞参数据预处理进行了研究,提出了基于残差检验的野值别除方法和基于神经网络的两阶段属性选择方法。在野值剔除方法中,首先计算原始序列和拟合序列的残差.再用门限值对残差进行检验;在属性选择方法中,先用神经网络对属性的相对重要度进行排序,再用神经网络进行属性选择。最后用实验验证了两方法的有效性。 相似文献
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依据某航天类项目的应用,提出了实时观测系统中数据引导的补偿方法,针对实时系统中的数据野值提出了剔除策略,给出了数据延迟问题的解决办法,并通过实例演示了编程实现,该方法对航天测控类应用具有普遍意义。 相似文献
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依据某航天类项目的应用,提出了实时观测系统中数据引导的补偿方法,针对实时系统中的数据野值提出了剔除策略,给出了数据延迟问题的解决办法,并通过实例演示了编程实现,该方法对航天测控类应用具有普遍意义. 相似文献
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Wireless sensor networks (WSNs) have been increasingly available for monitoring the traffic, weather, pollution, etc. Outlier detection in WSNs is an essential step for many important applications, such as abnormal event detection, fraud analysis, etc. While existing efforts focus on identifying individual outliers from sensory data, the unsupervised high semantic outlier detection in WSNs is more challenging and has received far less attentions. In addition, the correlation between multi-dimensional sensory data has not yet been considered when detecting outliers in WSNs. In this paper, based on multi-dimensional Hidden Markov Models, we propose a trajectory-based outlier detection algorithm by model training and model-based likelihood estimation. Our data preprocessing, clustering, model training and model updating schemes are developed to reduce the computational complexity and enhance the detecting performance. We also explore the possibility and feasibility of adapting the proposed algorithm to real-time outlier detections. Experimental results show that our methods achieve good performance on detecting various kinds of abnormal trajectories composed of multi-dimensional data. 相似文献
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针对分布复杂且离群类型多样的数据集进行离群检测困难的问题,提出基于相对距离的反k近邻树离群检测方法RKNMOD(Reversed K-Nearest Neighborhood).首先,将经典欧氏距离、对象局部密度和对象邻域结合,定义了对象的相对距离,能同时有效检出全局和局部离群点.其次,以最小生成树结构为基础,采取最大边切割法以快速分割离群点和离群簇.最后,人工合成数据集和UCI数据集试验均表明,新算法的检测准确率更高,为分布异常且离群类型多样的数据集的离群检测提供了一条有效的新途径. 相似文献
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Outlier detection techniques play an important role in enhancing the reliability of data communication in wireless sensor networks (WSNs). Considering the importance of outlier detection in WSNs, many outlier detection techniques have been proposed. Unfortunately, most of these techniques still have some potential limitations, that is, (a) high rate of false positives, (b) high time complexity, and (c) failure to detect outliers online. Moreover, these approaches mainly focus on either temporal outliers or spatial outliers. Therefore, this paper aims to introduce novel algorithms that successfully detect both temporal outliers and spatial outliers. Our contributions are twofold: (i) modifying the Hampel Identifier (HI) algorithm to achieve high accuracy identification rate in temporal outlier detection, (ii) combining the Gaussian process (GP) model and graph‐based outlier detection technique to improve the performance of the algorithm in spatial outlier detection. The results demonstrate that our techniques outperform the state‐of‐the‐art methods in terms of accuracy and work well with various data types. 相似文献
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分布式数据流上的连续异常检测 总被引:1,自引:1,他引:0
王树广 《微电子学与计算机》2008,25(9)
近年来,数据流异常检测在决策支持和监测等领域有着广泛的应用前景,并成为数据管理与挖掘的研究热点.针对该问题提出了相应的异常定义及检测算法,理论分析表明:与现有异常检测算法相比较,提出的算法具有良好的性能和效率,更适合于数据流应用. 相似文献
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This paper presents a robust method for outlier detection and correction in structure from motion. Aiming at handling outliers together with missing data, the Discrete Cosine Transform (DCT) based Column Space Fitting (CSF) algorithm is extended and improved. The use of the DCT basis allows for a coarse-to-fine optimization strategy that reconstructs 3D scene geometry and camera motion by increasing the number of DCT basis vectors. With a certain DCT basis, an interior point based L1-norm solver is used to successively estimate 3D scene structure. In addition, the fidelity of the estimated camera motion matrix is first integrated into an extension of Huber M-estimator to find outliers and to robustly estimate the update magnitude for each outlier. This fidelity can be measured by the effects of camera motion matrix on re-projection errors. Because the Huber M-estimator is only applicable to vector, we extend it into the matrix form. With the increase in the number of DCT basis vectors, outliers are corrected in a coarse-to-fine manner. Experiments on both synthetic and real image sequences confirm the effectiveness of the proposed method. 相似文献